Project II.2.4a: Determining ecosystem energy flow - Columbia River estuary methane biogeochemistry

Project Name: II.2.4a Determining ecosystem energy flow - Columbia River estuary methane biogeochemistry Methane Biogeochemistry
Project Leads: Fredrick Prahl, Joe Needoba and Tawnya Peterson

Project Description
Rivers throughout the world are in many cases orders of magnitude super-saturated in methane. Although this fact is now well documented, the environmental factor(s) controlling the level of methane super-saturation in these river systems remain poorly understood. Currently, the assumed dominant sink for ‘excess’ methane in river waters is degassing into the atmosphere where it can act as a potent greenhouse gas. However, oxidative consumption by riverborne methylotrophs represents a recognized, alternative sink which would diminish the greenhouse impact. At present, the importance of this alternative sink is appreciated only qualitatively.

This project is cast to study the spatial and temporal dynamics of methane biogeochemistry in the Columbia River and its estuary. A key goal is to evaluate the relative importance of methylotrophy versus river-to-air gas exchange as a sink for methane along the river-to-estuary continuum of the Columbia as it exists today.

Fit in program
(a) Relevance to global carbon cycle and climate change research. (b) Interdisciplinary project aimed to align scientific specialists who traditionally have not worked collaboratively together. (c) Designed to promote development and use of SATURN chemical sensors for effective environmental problem solving purposes.

Outcomes
Once armed with a mechanistic understanding of methane cycline, the project is aimed ultimately to assess how past changes, both natural and anthropogenic, in the watershed of this major river have altered this relative importance.